To improve maritime security and enhance international shipping commerce within US ports in addition to ISPS (International Ship and Port Facility Security Code), the TWIC (Transportation Worker Identification Credential) program is working on the maritime field from the October 15, 2008 in the United States. In this paper, the program is reviewed and investigated in terms of goal, benefit, solution, and related legislation so forth In addition, other maritime security programs including MMD (Merchant Mariner Document), FAST (Free and Secure Trade), SIDA (Security Identification Display Areas). and Air Cargo security program was analyzed and compared in order to obtain relationship and difference with the program in terms of enrollment frequency, list and method of security check, and profile of each program As a result of this paper, the program is mostly to improve maritime security, protect individual privacy, and enhance commerce rather than other programs.